Prior to the present invention, typical test fixtures for testing the sealing characteristics of O-ring gaskets used as bore seals were of two types. First, there was the totally static fixture. This fixture, as its name implies, checked O-ring performance under a totally static configuration, i.e., neither surface in contact with the O-ring was allowed to move. The second type was a partially dynamic test fixture. Under this configuration, one of the surfaces in contact with the O-ring was allowed to rotate with respect to the O-ring during the test. In addition, axial movement across the face of the O-ring could also be simulated with the second test fixture. However, neither fixture could check the response of an O-ring gasket where there was radial movement of the sealing surface away from the O-ring, i.e., where the space or gap filled by the O-ring became enlarged.
The present invention was first discussed in NASA test reports covering various results of testing performed on the invention. One report was dated January 1987 and the other one was dated Dec. 22, 1987. Both reports were authored by James E. Turner, a coinventor of the present invention, and were restricted to NASA personnel and NASA contractors only. The invention was first disclosed to the public at a conference in a paper entitled "Evaluation of the Sealing Ability of Various O-ring Materials for the Space Shuttle Redesigned Solid Rocket Motor," which was presented on June 7, 1988.